This guide will cover how to add a temperature/humidity sensor to Home Assistant using MQTT and Circuit Python. It is assumed that you already have a Home Assistant server up and running and that you have already installed the Mosquitto broker Add-on.

No soldering is required for this project, its plug-and-play thanks to the Metro ESP32-S2's STEMMA QT port and the many QT-friendly sensors we've got. Simply plug in the sensor and run the code to make customizable projects with sensing and Home Assistant!

This guide shows you how to configure the SHTC3 Humidity and Temperature sensor for Home Assistant, though other sensors can be used with just a little modification. This particular sensor has a wide range of temperatures, excellent accuracy, has low power consumption and has a Stemma QT port for plug and play without soldering. You can read more about this sensor in our Adafruit Sensirion SHTC3 - Temperature & Humidity Sensor Breakout guide.

For the main board, an ESP32-S2 is used because of the great combination of the built-in WiFi and the StemmaQT, but if you have another board that can connect to WiFi, runs CircuitPython, and can have your sensor wired up to it, that will work as well.

Parts List

Optionally add a battery for mobility or backup protection.